Update Broker service configuration dynamically (apache#186)

docs/AdminTools.md

@@ -14,6 +14,9 @@
 		- [Brokers](#brokers)
 			- [list of active brokers](#list-of-active-brokers)
 			- [list of namespaces owned by a given broker](#list-of-namespaces-owned-by-a-given-broker)
+			- [update dynamic configuration](#update-dynamic-configuration)
+			- [get list of dynamic configuration name](#get-list-of-dynamic-configuration-name)
+			- [get value of dynamic configurations](#get-value-of-dynamic-configurations)
 		- [Properties](#properties)
 			- [list existing properties](#list-existing-properties)
 			- [create property](#create-property)
@@ -233,6 +236,157 @@ GET /admin/brokers/{cluster}/{broker}/ownedNamespaces
 admin.brokers().getOwnedNamespaces(cluster,brokerUrl)
 ```
 
+#### update dynamic configuration
+Broker can locally override value of updatable dynamic service-configurations that are stored into zookeeper. This interface allows to change the value of broker's dynamic-configuration into the zookeeper. Broker receives zookeeper-watch with new changed value and broker updates new value locally.
+
+###### CLI
+
+```
+$ pulsar-admin brokers update-dynamic-config brokerShutdownTimeoutMs 100
+```
+
+```
+N/A
+```
+
+###### REST
+
+```
+GET /admin/brokers/configuration/{configName}/{configValue}
+```
+
+###### Java
+
+```java
+admin.brokers().updateDynamicConfiguration(configName, configValue)
+```
+
+#### get list of dynamic configuration name
+It gives list of updatable dynamic service-configuration name.
+
+###### CLI
+
+```
+$ pulsar-admin brokers list-dynamic-config
+```
+
+```
+brokerShutdownTimeoutMs
+```
+
+###### REST
+
+```
+GET /admin/brokers/configuration
+```
+
+###### Java
+
+```java
+admin.brokers().getDynamicConfigurationNames()
+```
+
+#### get value of dynamic configurations
+It gives value of all dynamic configurations stored in zookeeper
+
+###### CLI
+
+```
+$ pulsar-admin brokers get-all-dynamic-config
+```
+
+```
+brokerShutdownTimeoutMs:100
+```
+
+###### REST
+
+```
+GET /admin/brokers/configuration/values
+```
+
+###### Java
+
+```java
+admin.brokers().getAllDynamicConfigurations()
+```
+
+#### Update dynamic configuration
+Broker can locally override value of updatable dynamic service-configurations that are stored into zookeeper. This interface allows to change the value of broker's dynamic-configuration into the zookeeper. Broker receives zookeeper-watch with new changed value and broker updates new value locally.
+
+###### CLI
+
+```
+$ pulsar-admin brokers update-dynamic-config brokerShutdownTimeoutMs 100
+```
+
+```
+N/A
+```
+
+###### REST
+
+```
+GET /admin/brokers/configuration/{configName}/{configValue}
+```
+
+###### Java
+
+```java
+admin.brokers().updateDynamicConfiguration(configName, configValue)
+```
+
+#### Get list of dynamic configuration name
+It gives list of updatable dynamic service-configuration name.
+
+###### CLI
+
+```
+$ pulsar-admin brokers list-dynamic-config
+```
+
+```
+brokerShutdownTimeoutMs
+```
+
+###### REST
+
+```
+GET /admin/brokers/configuration
+```
+
+###### Java
+
+```java
+admin.brokers().getDynamicConfigurationNames()
+```
+
+#### Get value of dynamic configurations
+It gives value of all dynamic configurations stored in zookeeper
+
+###### CLI
+
+```
+$ pulsar-admin brokers get-all-dynamic-config
+```
+
+```
+brokerShutdownTimeoutMs:100
+```
+
+###### REST
+
+```
+GET /admin/brokers/configuration/values
+```
+
+###### Java
+
+```java
+admin.brokers().getAllDynamicConfigurations()
+```
+
+
 
 ### Properties
 

pulsar-broker-common/src/main/java/com/yahoo/pulsar/broker/ServiceConfiguration.java

@@ -62,6 +62,7 @@ public class ServiceConfiguration implements PulsarConfiguration{
     private long zooKeeperSessionTimeoutMillis = 30000;
     // Time to wait for broker graceful shutdown. After this time elapses, the
     // process will be killed
+    @FieldContext(dynamic = true)
     private long brokerShutdownTimeoutMs = 3000;
     // Enable backlog quota check. Enforces action on topic when the quota is
     // reached

pulsar-broker-common/src/main/java/com/yahoo/pulsar/common/configuration/FieldContext.java

@@ -56,4 +56,11 @@
      * @return character length of field
      */
     public int maxCharLength() default Integer.MAX_VALUE;
+
+    /**
+     * allow field to be updated dynamically
+     * 
+     * @return
+     */
+    public boolean dynamic() default false;
 }

pulsar-broker/src/main/java/com/yahoo/pulsar/broker/admin/Brokers.java

@@ -15,32 +15,48 @@
  */
 package com.yahoo.pulsar.broker.admin;
 
+import static com.yahoo.pulsar.broker.service.BrokerService.BROKER_SERVICE_CONFIGURATION_PATH;
+
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
 import javax.ws.rs.GET;
+import javax.ws.rs.POST;
 import javax.ws.rs.Path;
 import javax.ws.rs.PathParam;
 import javax.ws.rs.Produces;
 import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response.Status;
 
+import org.apache.bookkeeper.util.ZkUtils;
+import org.apache.zookeeper.CreateMode;
+import org.apache.zookeeper.ZooDefs;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.google.common.collect.Maps;
+import com.yahoo.pulsar.broker.ServiceConfiguration;
+import com.yahoo.pulsar.broker.loadbalance.impl.SimpleLoadManagerImpl;
+import com.yahoo.pulsar.broker.service.BrokerService;
+import com.yahoo.pulsar.broker.web.RestException;
+import com.yahoo.pulsar.common.policies.data.NamespaceOwnershipStatus;
+import com.yahoo.pulsar.common.util.ObjectMapperFactory;
+import com.yahoo.pulsar.zookeeper.ZooKeeperDataCache;
+
 import io.swagger.annotations.Api;
 import io.swagger.annotations.ApiOperation;
 import io.swagger.annotations.ApiResponse;
 import io.swagger.annotations.ApiResponses;
-import com.yahoo.pulsar.broker.loadbalance.impl.SimpleLoadManagerImpl;
-import com.yahoo.pulsar.broker.web.RestException;
-import com.yahoo.pulsar.common.policies.data.NamespaceOwnershipStatus;
+
 
 @Path("/brokers")
 @Api(value = "/brokers", description = "Brokers admin apis", tags = "brokers")
 @Produces(MediaType.APPLICATION_JSON)
 public class Brokers extends AdminResource {
     private static final Logger LOG = LoggerFactory.getLogger(Brokers.class);
-
+    private int serviceConfigZkVersion = -1;
+
     @GET
     @Path("/{cluster}")
     @ApiOperation(value = "Get the list of active brokers (web service addresses) in the cluster.", response = String.class, responseContainer = "Set")
@@ -79,4 +95,91 @@ public Map<String, NamespaceOwnershipStatus> getOwnedNamespaes(@PathParam("clust
             throw new RestException(e);
         }
     }
+
+    @POST
+    @Path("/configuration/{configName}/{configValue}")
+    @ApiOperation(value = "Update dynamic serviceconfiguration into zk only. This operation requires Pulsar super-user privileges.")
+    @ApiResponses(value = { @ApiResponse(code = 204, message = "Service configuration updated successfully"),
+            @ApiResponse(code = 403, message = "You don't have admin permission to update service-configuration"),
+            @ApiResponse(code = 404, message = "Configuration not found"),
+            @ApiResponse(code = 412, message = "Configuration can't be updated dynamically") })
+    public void updateDynamicConfiguration(@PathParam("configName") String configName, @PathParam("configValue") String configValue) throws Exception{
+        validateSuperUserAccess();
+        updateDynamicConfigurationOnZk(configName, configValue);
+    }
+
+    @GET
+    @Path("/configuration/values")
+    @ApiOperation(value = "Get value of all dynamic configurations' value overridden on local config")
+    @ApiResponses(value = { @ApiResponse(code = 404, message = "Configuration not found") })
+    public Map<String, String> getAllDynamicConfigurations() throws Exception {
+        ZooKeeperDataCache<Map<String, String>> dynamicConfigurationCache = pulsar().getBrokerService()
+                .getDynamicConfigurationCache();
+        Map<String, String> configurationMap = null;
+        try {
+            configurationMap = dynamicConfigurationCache.get(BROKER_SERVICE_CONFIGURATION_PATH)
+                    .orElseThrow(() -> new RestException(Status.NOT_FOUND, "Couldn't find configuration in zk"));
+        } catch (RestException e) {
+            LOG.error("[{}] couldn't find any configuration in zk {}", clientAppId(), e.getMessage(), e);
+            throw e;
+        } catch (Exception e) {
+            LOG.error("[{}] Failed to retrieve configuration from zk {}", clientAppId(), e.getMessage(), e);
+            throw new RestException(e);
+        }
+        return configurationMap;
+    }
+
+    @GET
+    @Path("/configuration")
+    @ApiOperation(value = "Get all updatable dynamic configurations's name")
+    public List<String> getDynamicConfigurationName() {
+        return BrokerService.getDynamicConfigurationMap().keys();
+    }
+
+    /**
+     * if {@link ServiceConfiguration}-field is allowed to be modified dynamically, update configuration-map into zk, so
+     * all other brokers get the watch and can see the change and take appropriate action on the change.
+     * 
+     * @param configName
+     *            : configuration key
+     * @param configValue
+     *            : configuration value
+     */
+    private synchronized void updateDynamicConfigurationOnZk(String configName, String configValue) {
+        try {
+            if (BrokerService.getDynamicConfigurationMap().containsKey(configName)) {
+                ZooKeeperDataCache<Map<String, String>> dynamicConfigurationCache = pulsar().getBrokerService()
+                        .getDynamicConfigurationCache();
+                Map<String, String> configurationMap = dynamicConfigurationCache.get(BROKER_SERVICE_CONFIGURATION_PATH)
+                        .orElse(null);
+                if (configurationMap != null) {
+                    configurationMap.put(configName, configValue);
+                    byte[] content = ObjectMapperFactory.getThreadLocal().writeValueAsBytes(configurationMap);
+                    dynamicConfigurationCache.invalidate(BROKER_SERVICE_CONFIGURATION_PATH);
+                    serviceConfigZkVersion = localZk()
+                            .setData(BROKER_SERVICE_CONFIGURATION_PATH, content, serviceConfigZkVersion).getVersion();
+                } else {
+                    configurationMap = Maps.newHashMap();
+                    configurationMap.put(configName, configValue);
+                    byte[] content = ObjectMapperFactory.getThreadLocal().writeValueAsBytes(configurationMap);
+                    ZkUtils.createFullPathOptimistic(localZk(), BROKER_SERVICE_CONFIGURATION_PATH, content,
+                            ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
+                }
+                LOG.info("[{}] Updated Service configuration {}/{}", clientAppId(), configName, configValue);
+            } else {
+                if (LOG.isDebugEnabled()) {
+                    LOG.debug("[{}] Can't update non-dynamic configuration {}/{}", clientAppId(), configName,
+                            configValue);
+                }
+                throw new RestException(Status.PRECONDITION_FAILED, " Can't update non-dynamic configuration");
+            }
+        } catch (RestException re) {
+            throw re;
+        } catch (Exception ie) {
+            LOG.error("[{}] Failed to update configuration {}/{}, {}", clientAppId(), configName, configValue,
+                    ie.getMessage(), ie);
+            throw new RestException(ie);
+        }
+    }
+
 }